In horizontal filter presses, a filter chamber is formed between two sheet-like filter media horizontally pressed between adjacent vertical filter plates. Hence, the name horizontal filter press. Each filter medium is equipped with a filling shoe enabling slurry to be fed from a slurry duct into the filter chamber via slurry passages. Particularly, the slurry duct may be formed by aligned openings provided on the succession of filter plates, filling shoes and filter media. The slurry passage, in turn, may be formed by the opposing filling shoes of the two filter media by a form extending from the opening of the duct towards the chamber.
Thus, the purpose of the filling shoe is to provide a route for feeding slurry in between two filter media, and to form a part of a common slurry duct.
A conventional filling shoe comprises a body having a slurry opening. From the opening, the filling shoe may comprise a form such as a groove extending towards the filter chamber. The conventional filling shoe also comprises an annular flange surrounding the slurry opening, wherein an annular groove is formed on the flange, extending radially with respect to the slurry opening such that the annular groove resides between the flange and the rest of the body. The conventional filling shoe is attached to a filter medium by inserting the flange through a corresponding opening in the filter medium, such that the filter medium is placed in the annular groove between the flange and the rest of the body. Moreover, conventional filling shoes have been equipped with a stud extending from the body into a corresponding recess in the flange within the annular groove for securing the rotational position of the filling shoe with respect to the filter medium. The stud has been arranged to extend through an opening in the filter medium dedicated for rotationally orienting the filling shoe to the filter medium.
The construction of the conventional filling shoe, particularly the stud, has mandated the filling shoe to be formed in a two-piece form. In practise, the flange part and the rest of the body have been formed separately, and subsequently adhered to each other to form the filing shoe. This, in turn, has led to unsatisfactory durability of the filling shoe. Notably, the joint between the flange part and the rest of the body has proven to break apart over time under the forces exerted on filling shoe by the filter press.